1. Field of the Invention
The present invention relates to a lubricant-tight vane rotary vacuum pump having a pump stage including a pump stage housing having inlet and outlet, and a compression chamber located in the housing.
2. Description of the Prior Art
Lubricant-tight vane rotary vacuum pumps are used for many years in many industries for producing low and high vacuum. In addition to traditional requirements the vacuum technology should meet, modern vane rotary vacuum pumps should have additional characteristics one of which is a reduced operating noise generated by a pump and transmitted to the environment.
European Publication EP-A 1 696 131 suggests to arrange a vane rotary vacuum pump in an external housing to noise-isolate the pump. The problem with this solution is high costs of the external housing and a danger of the pump, which is enclosed in a small closed volume, to overheat during operation.
Accordingly, the object of the invention is to provide a cost-effective construction of a vane rotary vacuum pump that would have a reduced noise.